function [ac, as, fc, fs] = amp_phase(obj, x, z0, zc, p, nmax)
%AMP_PHASE Summary of this function goes here
%   Detailed explanation goes here
    if nargin == 4
        nmax = 10;
    end
    
    [wp, wm, qp, qm] = obj.WQ(x, z0, zc, p, nmax);
    
    ac = sqrt( (qp+qm)*(qp+qm) + (wp-wm)*(wp-wm) );
    as = sqrt( (qp-qm)*(qp-qm) + (wp+wm)*(wp+wm) );
    fc = atan2( wp-wm, qp+qm );
    fs = atan2( wp+wm, qp-qm );
end

